Pump



Patented Sept. 5, 1950 l PUMP Donald R.V Spotz, Lakewood, Ohio, assignorto Thompson Products, Inc., Cleveland, Ohio, a

corporation of Ohio Application september 1s, 1944, serial No. 553,811

This invention relates. to a simplified positive displacement vane typepump that is inexpensive and easy to manufacture.

Specifically, the invention relates to a vane type pump for mounting ona prime mover such as an aircraft engine to be driven thereby and havinga casing equipped with a readily removable end cap on-the end thereofremote from the prime mover mounted end together with pump parts insideof the casing adapted to be readily removed through said remote end uponremoval of the end cap.

The invention will be hereinafter specifically described as embodied inan aircraft engine fuel pump of the type disclosedI in the Russell R.'

Curtis yPatent No. 2,268,805, dated January 6. 1942, but it should beunderstood that the principles of this invention are generallyapplicable to other types of pumps. It should also be understood thatthe pumps of this invention are useful for pumping many different typesof fluids including water, solvents such as alcohol, gasoline, oil andthe like. l

In general the pumps of this invention include a casing having an endwall portion adapted Ato t into the aperture of a prime mover. This endwall has a small central aperture for receiving a shaft therethrough tobe coupled with the prime mover. The casing has an open end remote fromlthe end wall.' A readily removable cap is provided for closing this openend. All of the pump parts are held in the casing between the end walland the removable end cap, and are so designed that they can beretracted from the casing by removal of the end cap. The pumps of thisinventionjtherefore, can beserviced without separating them from theprime mover on which they may be mounted.

It is, then, an object of this invention to provide a pump and casingassembly arranged for mounting on a prime mover and having a readilyremovable end cap closing an opening through which all of the pump partscan be retracted without disconnecting the assembly from the primemover.

A further object of the invention is to provide a simplified positivedisplacement type pump and casing assembly arranged so that all of thepump parts in the casing assembly are held in position by a removableend cap and are removed from the casing through the end closed by theremovable end cap.

A still further object of theinvcntion is to pro` vide a simplifiedpositive displacement pump that is easily assembled and disassembled,and is inexpensive to manufacture.

A still further object of the invention is to provide a universal typepump adapted to handle fluids of all natures and-adapted to be quicklyrepaired.

4 claims. (cl. 10s-137) A further object of this invention is to providea pump and seal assembly for quick installation in a. casing arranged tobe readily removed from the casing upon removal of a single end cap onthe casing.

Other and further objects of the invention will be apparent to thoseskilled in the art from the following detailed description of theannexed sheet of drawings which, by way of preferred example only,illustrates one embodiment of the invention. f

On the drawings:

Figure 1 is a top plan view of a pump according to this inventionmounted on an engine part shown in horizontal cross section.

Figure 2 is avertical cross-sectional view, with parts in sideelevation, of the assembly shown in Figure 1 taken along the line II-JIof Figure 1.

Figure 3 isl an exploded view illustrating the manner in which thepumpparts are readily removed from the pump casing without removal ofthe casing from the engine.

As shown on the drawings:

The pump assembly I0 of this invention is mounted on an engine part IIand includes a main pump casing or housing I2. a by-.pass and reliefvalve casing I3 mounted on top of the v casing I2, and a spring casingI4 mounted on top of the valve casing I3. The casings I3 and Ill and theparts therein are described in the hereinbefore referred to CurtisPatent 2,268,805.

The pump casing I2 has an inlet port I2a and an outlet port I2b onopposite sides thereof together with an 'end wall I2c at one end thereofprojecting forwardly from a surrounding mounting flange I2d. The casingI2 has an open end I2e remote from the wall I2C but in axial alignmenttherewith. The casing I2 thus denes a cylindrical chamber open at oneend I 2e thereof and closed at the other end I2C thereof. The end I2chas a central aperture I2f therethrough.

The engine part II includes a .pad I5 with an aperture I5a therethroughreceiving the end wall I2c in snug engagement therewith. This end wallI2c thus acts as a pilot portion for aligning the pump on the enginepart. A gasket or sealing washer I6 overlies the pad I5 and ispositioned between the pad and the mounting face of the mounting `flangeI2d.

Studs I'I project from the pad I5 at spaced intervals and extend throughthe mounting flange I2d. Nuts I8 threaded on the studs I'I clamp theflange in fixed relation on the pad,

thereby securing the pump assembly I0 to the A thrust washer |9 composedof an oil-impregnated sinteredv bronze or other oil-retaining bearingmaterial is seated in the casing |2 against; the end wall |2c thereof.This washer |9 has a chamfered central aperture |9a therethrough.

A splined driver or pump shaft has a first splined end 20a adapted toproject into the engine part to be coupled with the engine drive. Thedriver 20 has a shaft portion 20h which fits freely in the aperture Isaof the washer I9 and |2f of the end wall |2e. A rounded collar portion20c is formed on the driver adjacent the cylindrical shaft portion 2Gbthereof and this collar rides on the chamfered aperture |9a of thewasher I9, in rockable relation.

The driver has a smaller splined end 20d remote from the end 20a thereofwhich is splined into the hollow hub .2| a of the pump rotor 2|. Therotor 2| has a second hub 2| b at the opposite end thereof.

The hub 2 la is hollow and has a plug 22 pressed therein inwardly fromits end. A coil spring 23 is compressed between the plug 22 and thesplined end 20d of the driver 20 to urge the driver outwardly from therotor hub so that its collar 20c will continually seat on the chamferedaperture |9a of the thrust washer |9. A ball and socket jointrelationship between the driver and the thrust washer is obtained.

The rotor 2| ts freely into the casing l2 and is rotatably supportedtherein on bearing rings 24 and 25 which can be formed of graphiticcarbon or the like plain bearing material. The bearing 24 rotatablysupports the rotor hub 2|a while the bearing 25 rotatably supports therotor hub 2lb..

A pump liner 26 is snugly tted in the casing I2 between the bearings 24and 25 and around a central enlarged portion 2|c of the rotor 2|. Theliner 26 has an eccentric inner bore 26a cooperating with the exteriorsurface of the central hub portion 2 Ic to define therebetween thepumping chamber for the pump. The liner has apertures aligned With thecasing ports |2a and |2b so that the pumping chamber is in communicationwith these ports.

I he central portion of the rotor 2| has a pair of slots such as theslot 21 therethrough in right angular relationship. These slots,slidably support the pumping vanes such as 28. The pumping vanes haveintermediate tongues but their peripheral portions provide continuoussurfaces in the pumping chamber.

The liner 26 Ais held against rotation in the casing |2 by means of alock clip 29 which ts in a recess such as recess 2Gb in the liner whichcan be conveniently formed by a milling cutter. The clip 29 is insertedthrough an aperture |21' in the casing l2.

A stationary seal ring 30 composed of graphitic carbon or similarmaterial has a grooved end face seated on the thrust washer I9 andcooperating therewith to dene grooves 3| which will drain any liquidwhich may leak past the end seal face of ring 30, to passageways 32connecting the interior of the casing with the inner ends of thethreaded plugs |2g.

An O ring 33, composed of resilient rubber-like material capable ofresisting aromatic solvents is urged against the peripheral portion ofthe stationary seal ring 30 by a washer 34 acted on by a spring 35 whichis compressed between the washer and the bearing 24. This O ring willseal the peripheral portion of the stationary seal ring 30 in thecasing.

' A rotating seal ring 36 composed of Monel 4: y metal or the likematerial is disposed around the hub 2|a and has an end face riding onthe stationary seal ring 30. A Phosphor gbronze or stainless steel wireclip 31 is'snapped into. the hub 2 la of the rotor and fits in aninternal groove in' the rotating seal ring 36 to form akey `connectiontodrive the rotating seal ring with the rotor.

A synthetic rubber rsleeve 38 embraces the rotating seal ring 36 and hasa beaded end seated in a peripheral groove on the rotating seal ring 36.The sleeve 38 snugly engages the hub 2|a and is tightly secured thereonby means of a lock wire39. A metal cup 40 embraces the portion of thesleeve disposed around the seal ring 36 and is urged by a spring 4| tomove the seal ring against the stationary ring 30. The spring 4| isbottomed on a washer 42 which is held against axial movement on the hub2 la by a lock wire 43.

The plug 22 prevents leakage through the rotor hub 2|a. The sealassembly including vthe stationary seal ring 30, the rotating seal 36,and the rubber sleeve 39 prevents leakage of material around the rotorhub 2 la, However, if the seal between the rotating and stationary sealrings should leak, the leaked material will be drained through thegrooves 3| into a passageway 32.

The driver 20 is free to wobble, since it is rockably splined in the hub2|a, but wobbling movements of the driver will not unevenly load thebearings for the rotor. The driver at all times has sealing engagementwith the thrust washer 9 although it is free to rock and tilt on thiswasher. This sealing engagement prevents leakage of lubricating oil fromthe engine driver into and through the pump drain grooves 3| andpassageways 32. Likewise, this seal prevents any liquid leakage on theinterior of the pump past the driver 20 to the exterior of the pumpthrough the central aperture |2f.

The open end |2e of the casing |2 is closed by an end cap 44 which is inthe nature of a stamped metal plate preferably composed of stainlesssteel. A gasket or sealing washer 45 is interposed between the end ofthe casing and the plate 44. Cap screws 46 are passed through the endcap 44 and are threaded into the casing to secure the end cap to thecasing. The end cap abuts the bearing 25 and cooperates with the endwall |2e of the casing to clamp all of the pump parts therebetween.

When the end cap 44 is removed from the casing I2, as illustrated inFigure 3, all of the pump parts are readily retracted through the openend |2e of the casing and can be replaced or repaired withoutdisconnecting the casing from the engine part The spring 35 acts as aresilient take-up means for the O ring seal 33 should this part take acompression set. When the end cap 44 is removed, the spring 35 aids inthe removal of the pump parts, since it tends to force the bearingy `orreplaced without difficulty.

ment with the end wall in spaced relation therep from, a mounting flangeon said casing sur- 'rounding said end wall, a pump shaft extendingfreely through the aperture in said end wall, said pump shaft having ashoulder disposed in the casing, a thrust washer bottomed on saidapertured end wall, said thrust washer having a beveled aperturereceiving said shoulder of the drive shaft in tiltable relation thereon,a stationary seal ring having one face thereof bottomed on said thrustwasher, an O ring in said casing bottomed on the peripheral portion ofthe other face of said stationary seal ring, a washer overlying said 0ring, a rotating seal ring having an end face riding `on said other faceof the stationary seal ring, a pump rotor in said casing having hubs atthe ends thereof with one of the hubs extending through and keyed to therotating seal ring, bearing rings seated in said casing rotatablysupporting'said rotor hubs, a pump liner between said bearing ringscooperating with said rotor to dene therebetween a pumping chamber,pumping vanes carried by said rotor, a spring compressed between saidwasher overlying the 0 ring and the bearing ring adjacent said washer, aremovable end cap secured to the open end of said casing thrustingagainst the other of said bearings cooperating with said apertured endwall to clamp the pump parts inthe casing, and all of said parts in saidcasing being arranged for removal through the open end of the casing.

2. A pump comprising Va casing having a peripheral wall, a flanged endwith an apertured end wall and an open end opposite the apertured endwall, said flanged-end being arranged for attachment to an engine pad, aliner in said casing, bearing rings in said casing bottomed'on oppositeends of said liner, a pump rotor in saidl casing rotatable in saidbearing rings, pumping vanes carried by said rotor, a hub on said rotorprojecting through one of said bearing rings, a driver for said rotorprojecting through the apertured end wall of the casing, said driverhaving a shoulder portion in the casing of larger diameter than theaperture in said end wall, means in said casing receiving said shoulderin tiltable relation, a stationary seal ring bottomed on said means, arotating seal ring riding on said stationary seal ring, a washer on saidhub of the rotor, a nrst spring bottomed on said rotating seal ring andon said washer to maintain the rotating seal ring in sliding sealingengagement with the stationary seal ring, a second spring compressedbetween said stationary seal ring and the adjacent bearing ring. and anend 'cap removably secured to the open end of the casing in thrustingrelation tothe other bear- .ing ring whereby .removal of said end capalon opposite sides of said liner, a pump rotor in said casing rotatablein said bearing rings, pumping vanes carried by said rotor, a hubon saidrotor projecting through one of said bearing rings, a driver forA saidrotor projecting through the apertured end wall of said casing, saiddriver having a shoulder portion in the casing of larger diameter thanthe diameter of the aperture in said end Wall. means in said casingreceiving said shoulder in tiltable relation, a stationary seal ringbottomed on said means, an 0 ring having one face bottomed on saidstationary seal ring, a washer in surface engagement with the other faceof said 0 ring, a rotating seal ring riding on said stationary sealring, a second washer on said hub of the rotor, a spring bottomed onsaid rotating real ring and on said second washer to maintain therotating seal ring in sliding sealing engagement with the stationaryseal ring, a second spring compressed between said first washer and theadjacent bearing ring to maintain said O ring in sealing engagement withsaid stationary seal ring, and an end cap removably secured to the openend of the casing in thrusting relation to other bearing ring wherebyremoval of said end cap allows said second spring to urge pump parts outof the open end of the casing.

4. A pump comprising .a casing having an apertured end wall with amounting flange therearound for attachment to an engine, said casinghaving an open end remote from said apertured end wall, a lubricatedthrust washer seated against said end wall and having a chamferedaperture opening toward said open end and registering with the apertureof said end wall. a pump rotor rotatably disposed in said casing,pumping vanes carried by said rotor, a. drive shaft for said rotorextending through said aD- ertured end wall and said thrust washer, saidshaft having a peripherally rounded circumferopen end of the casing forclamping said ro tor and said seal parts between the end wall of ythecap against the action of said spring, said chamfered washer aperturefacilitating removal of said drive shaft and insuring sealing of saidshaft upon assembly. v

DONALD R, SPO'IZ.

anrEaENcEs cri-En The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,497,050 Wardell June 10, 19241,877,688 Petersen 1---- Sept. 13, 1932 2,112,522 Czarnecki. et al.Mar.` 29, 1938 2,131,968 Petersen Oct. 4, 1938 2,268,805 Curtis Jan. 6,1942 ,2,302,907 Eilers NOV. 24, 1942 2,348,679 Groves May 9, 19442,372,816 Deschamps et al. Apr. 3. 1945 3,380,783 Painter` July 31, 1945

